Exposing adolescent rats to THC disrupted normal maturation of a key set of neurons in a brain area that corresponds to the human prefrontal cortex. The disruptions produced structural differences that resemble patterns which have been observed in people with addiction and schizophrenia.
Legally protected marijuana dispensaries (LMDs) were associated with lower rates of dependence on prescription opioids, and deaths due to opioid overdose, than would have been expected based on prior trends. However, LMDs also were associated with higher rates of recreational marijuana use and increased potency of illegal marijuana.
A brain imaging study strongly suggests that regular users of marijuana have smaller orbitofrontal cortex (OFC) volumes. Such a deficit could make it more difficult to change counterproductive behaviors, including drug use.
These findings add to research showing that nicotine and cannabis have interactive effects on brain structure and function. They also suggest that specialized treatment interventions may be appropriate for people who use both drugs.
Researchers used the statistical technique of latent class analysis to describe distinct patterns of marijuana use across age using data from nearly 10,000 participants in the Monitoring the Future study. Longer-term marijuana use (extending from age 18 into the late 20s or beyond) was associated with increased risk of self-reported health problems at age 50.
The spread of marijuana use and the opioid epidemic over the past 10 years have affected middle-aged and older Americans. In addition, prescription opioid and benzodiazepine misuse increased older adults’ risk of suicidal thoughts.
People with cannabis dependence have changes in neural circuitry in brain regions related to reward processing, habit formation, and psychopathology. These changes in neural circuitry may provide a useful marker for tracking psychopathology associated with cannabis misuse.